The present invention is directed to a dispenser containing dual chambers. One of the chambers contains a substance to be mixed with another substance such as a diluent, in the other chamber. The chambers are maintained so that there is no flow between them during a storage period. When the dispenser is to be used, substances are mixed by introducing the substances from one chamber into the other.
In the past dual chamber dispensers have been used for solutions or mixtures having a relatively short use life. The two components of such a solution must be kept separate during shelf storage to prevent the deterioration of the solution prior to its use.
When the solution being used is a pharmaceutical or drug solution, it is important that the solution, when prepared for use, is maintained free of contamination. If contamination in the form of moisture, dust, gases in the ambient atmosphere and the like, enter the solution it is possible that the solution will be rendered unfit for use.